After its cancellation by CBS in 1967, it returned in syndication as a daily production which ran from 1968 until 1975. There have been several international versions, radio versions, and a live stage version.

In 2013, TV Guide ranked it #9 in its list of the 60 greatest game shows ever.[4]

Produced by Mark Goodson and Bill Todman for CBS Television, the show was initially called Occupation Unknown before deciding on the name What's My Line?.[5] The original series, which was usually broadcast live, debuted on Thursday February 2, 1950 at 8:00 p.m. ET. After airing alternate Wednesdays, then alternate Thursdays, finally on October 1, 1950 it had settled into its weekly Sunday 10:30 p.m. ET slot where it would remain until the end of its network run on September 3, 1967.

Starting in July 1959 (and continuing for 8 straight years until July 1967), when John Daly was due to appear in Moscow, the show would occasionally record episodes onto Quadruplex videotape, for playback at a future date. A then-state-of-the-art technology, which Daly praised, upon his return from Moscow.[6] In such instances, there would often be two shows a day; the "taped" one, followed immediately by the "live" one. The cast and crew began taking "Summer breaks" from the show in July 1961, through July 1967 [7]

In addition to the television version, What's My Line was also broadcast on network radio for a short time. From May 20, 1952 an NBC Radio version was produced on Tuesday nights with the same cast as the TV version. The program was then broadcast live on CBS Radio on Wednesday nights at 8:00 PM for 10 months concluding July 1, 1953.[8][9] The radio version is notable for the only appearances of Marlene Dietrich and Marlon Brando.

A Community Chest Special, completely separate from the regular production of episodes, was broadcast live on all the major networks (CBS, ABC, NBC, and Dumont) on the afternoon of Sunday September 27, 1953.[10]

The show featured a panel of four celebrities who questioned the contestants. On the initial program of February 2, 1950, the panel was former New Jersey governor Harold Hoffman, columnist Dorothy Kilgallen, poet Louis Untermeyer, and psychiatrist Richard Hoffmann. For the majority of the show’s run the panel consisted of Kilgallen, Random House publisher and co-founder Bennett Cerf, actress Arlene Francis and a fourth guest panelist. During the show’s earliest period the panel generally consisted of Kilgallen, Francis, Untermeyer and comedy writer Hal Block with Cerf replacing Untermeyer in 1951 and comedian Steve Allen replacing Block in 1953. Steve Allen left to launch The Tonight Show in 1954 and was replaced by comedian Fred Allen who remained on the panel until his death in 1956. After Kilgallen's death in 1965, the two remaining seats on the panel were never filled regularly again. The most frequent guest panelist was Arlene Francis' husband Martin Gabel, who appeared 112 times.

What’s My Line? was a guessing game in which four panelists attempted to determine the occupation of a guest. In the case of the famous mystery guest each week, the panel sought to determine the identity of the contestant. Panelists were required to probe by asking only yes-no questions. A typical episode featured two standard rounds (sometimes a third, and very rarely a fourth) plus one mystery guest round. On the occasions on which there were two mystery guests, the first would usually appear as the first contestant.

For the first few seasons, the contestant would first meet the panel up close, for a casual inspection, and the panel was allowed one initial guess. However, beginning in 1955 Daly simply greeted and seated the contestant, who then met the panel at the end of the game. The contestant's line was then revealed to the studio and television audiences, and Daly would tell the panel whether the contestant was salaried or self-employed, and from 1960 on, dealt in a product or a service.

A panelist chosen by Daly would begin the game. If his question elicited a yes answer, he continued questioning. When a question was answered no, questioning passed to the next panelist and $5 was added to the prize. The amount of the prize was tallied by Daly who flipped one of 10 cards on his desk. A contestant won the top prize of $50 by giving ten no answers, or if time ran out, with Daly flipping all the cards. As Daly occasionally noted, "Ten flips and they (the panel) are a flop!" Daly later explained, after the show had finished its run on CBS, the maximum payout of $50 was to ensure the game was played only for enjoyment, and that there could never be even the appearance of impropriety. Later in the series, Daly would throw all the cards over with increasing frequency and arbitrariness, evidence the prize was secondary to game play.

Panelists had the option of passing to the next panelist – or even disqualifying themselves entirely if they somehow knew before the game the contestant's occupation – and they could also request a conference, in which they had a short time to openly discuss ideas about occupations or lines of questioning.

Panelists adopted some basic binary search strategies, beginning with broad questions, such as whether the contestant worked for a profit-making or non-profit organization or whether the product was alive, worn, or ingested. To increase the probability of affirmative answers, panelists would often phrase questions in the negative starting with "Is it something other than..." or "Can I rule out..."

The show popularized the phrase "Is it bigger than a breadbox?", first posed by Steve Allen on January 18, 1953 then refined over subsequent episodes. Soon, other panelists were asking this question as well.[14][15] On one occasion the guest was a man who made breadboxes. It was correctly guessed by Allen after Kilgallen asked "Is it bigger than a breadbox" and Daly could not restrain his laughter.[16][17]

The final round of an episode involved blindfolding the panel for a celebrity "mystery guest" (originally called "mystery challengers" by Daly) whom the panel had to identify by name, rather than occupation. In the early years of the show, the questioning was the same as it was for regular contestants, but starting with the April 17, 1955 show, panelists were only allowed one question per turn. Mystery guests usually came from the entertainment world, either stage, screen, television or sports. When mystery guests came from other walks of life, or non-famous contestants whom the panel but not the studio audience might know, they were usually played as standard rounds. However, the panel might be blindfolded, or the contestant might sign in simply as "X", depending on whether he would be known by name or sight.

Mystery guests would usually attempt to conceal their identities with disguised voices, much to the amusement of the studio audience. According to Cerf, the panel could often determine the identity of the mystery guest early, as they knew which celebrities were in town, or which major movies or plays were about to open. On those occasions, to provide the audience an opportunity to see the guest play the game, the cast would typically allow questioning to pass around at least once before coming up with the correct guess.[18]

Sometimes, two mystery guest rounds were played in an episode, with the additional round usually as the first round of the episode.

What's My Line? is known for its attention to manners and class.[19] In its early years, business suits and street dresses were worn by the host and panelists, but by 1953, the men wore black suits with bow ties (a few guests in fact wore tuxedos) while female panelists donned formal gowns and often gloves.[20] Exceptions to this dress code were on the broadcasts immediately following the deaths of Fred Allen[21] and Dorothy Kilgallen,[22] in which the male cast members wore straight neckties and the women ordinary dresses instead of evening gowns.

The game followed a line of formality and adherence to rules. Although using first names at other points, Daly usually addressed using surnames when passing the questioning to a particular panelist. He would also amiably chide the panel[23] if they began a conference without first asking him.

However, even with such formality, Daly was not above trading bon mots with the panelists during the game and Bennett Cerf would often attempt to make a pun of his name. Occasionally Daly would amiably one-up Cerf if he felt the pun was of lesser quality. Cerf also played a myriad of games with Daly's full name (John Charles Patrick Croghan Daly) reciting it correctly only a handful of times over the course of the series.

Often Daly would need to clarify a potentially confusing question, but his penchant for verbose replies often left panelists more confused than before (which Danny Kaye once parodied as a panelist).[24] On more than one occasion, Daly "led the panel down the garden path" – a favorite phrase used when the panel was misled by an answer.

The program began with Daly and panel entering from off-stage as they were introduced. Prior to 1954, both panelists and host began the program in their seats, but this was changed, responding to letters asking what panelists looked like away from their seats. The first panelist would be introduced by the announcer following the show's introduction, and each panelist would introduce the next in turn, with the last introducing Daly. During his tenure, Hal Block sat in the final seat and began the practice of introducing Daly with a pun. Upon his departure, Bennett Cerf took over this position and expanded these introductions, often telling long jokes which he tied to Daly in some way.[25]

To begin a round, Daly would invite the contestant to "come in and sign in, please" which by 1960 evolved to the more familiar "enter and sign in, please." The contestant entered by writing his or her name on a small sign-in board. Daly would then usually ask where the guest lived and, with a woman, if she should be addressed as "Miss" or "Mrs." Early in the show's run, the panel was allowed to inspect contestants, studying their hands, or label on their suit or asking them to make a muscle.

While ostensibly a game show, if there was time, it also was an opportunity to conduct interviews. Line’s sister show, I've Got a Secret (and later the syndicated version of WML) engaged in the practice of contestants' demonstrating their talents. However, despite frequent requests by the panel (particularly Arlene Francis) such demonstrations rarely occurred as according to executive producer Gil Fates, Daly was not fond of this practice.[25]

After the first four episodes, the show gained its initial sponsor: Stopette spray deodorant made by Jules Montenier, Inc. This involved featuring the product in the show's opening, on the front of the panel's desk, above the sign-in board, and on Daly’s scorecards. Bennett Cerf explained that Dr. Montenier was ultimately ruined by his refusal to abandon or share sponsorship as the show entered new markets and became too expensive.[26][27] After Dr. Montenier sold Stopette to Helene Curtis,[28] the series was sponsored by a variety of companies which were either regular or rotating. Sponsors were accorded the same exposure on the set as Stopette. Near the end of its run, sponsors would be introduced in the opening title and given commercials during the show, but would not be displayed on the set. Frequent sponsors in the 1960s were Kellogg's cereals, Allstate Insurance, and Geritol.

Unknown to the public, mystery guests were paid $500 as an appearance fee, whether they won or lost the game. This was in addition to the maximum $50 game winnings, which guests sometimes donated to charity. Guest panelists were paid $750 as an appearance fee. The regular panelists were under contract and were paid "much more," according to Fates.[29]Bennett Cerf explained that when he became a permanent member of the program, he was paid $300 per week, and by the end of the series, they were being paid "scandalous amounts of money".[30][31]

From 1950 to 1966, the game show was broadcast in black-and-white, as was typical of most game shows at the time. But by 1966, all three networks had transitioned to broadcasting their prime-time schedules entirely in color. But after the show ended in 1967, CBS replaced the color videotapes with the kinescope versions instead for syndication. As a result of this change, the 1966-1967 episodes of What's My Line? were only shown in black-and-white after the show ended.[32]

Beginning with the first Wednesday episode (#005; April 12, 1950, and continuing until around 1951), the show was filmed at the now demolished CBS Studio 51 (Maxine Elliott's Theatre, aka Maxine Elliott Theatre, 109 W. 39th St., NY). [34]

Around 1951, the show moved to CBS Studio 59 (Mansfield Theatre, later renamed the Brooks Atkinson Theatre in 1960, 256 W. 47th St., NY), and stayed there until Episode #516, June 5, 1960.[35][36] Meanwhile, the concurrent 1952-1953 Radio edition, at least during the CBS run, was heard live from CBS Studio Building 22 (49 E. 52nd St., NY).[37]

In Episode #225 (September 19, 1954) a color edition of the show was broadcast live at CBS Studio 72 (On Manhattan's Upper West Side, Broadway at 81st St., NY). This predated the shows' eventual move to color by 12 years. [38][39]

In Episode #323 (August 12, 1956), in conjunction with the 1956 Democratic Party Convention, a special Chicago episode was shot, at the studios of the CBS Chicago affiliate of WBBM-TV (630 N. McClurg Ct., Chicago, IL).[40]

In Episode #397 (January 12, 1958), a special Hollywood episode was shot, at CBS Television City (7800 Beverly Blvd, Los Angeles, CA). The moderator and panel's desks were not brought over, like they were for the Chicago special.[41]

Beginning with episode #517, through episode #829 (June 12, 1960 to September 4, 1966), the show was filmed at CBS Studio 52 (254 W. 54th St., NY; the future Studio 54).[42] The last episode aired in black & white was taped on July 17, 1966, and the last episode to be produced there in black & white aired live on July 24.

For the final season, from episode #830 to episode #876 (September 11, 1966-September 3, 1967), in conjunction with the program's permanent move to color, the show was filmed at CBS Studio 50 (Later renamed the Ed Sullivan Theatre, 1697 Broadway at 53rd St., NY).[43]

CBS announced in early 1967 that a number of game shows, including What's My Line?, were to be canceled at the end of the season. Bennett Cerf wrote that the network decided that game shows were no longer suitable for prime time, and that the news was broken by the New York Times on February 14[44][45] before anyone involved with the show was notified.[46]

The 876th and final CBS telecast of What's My Line? aired on September 3, 1967; it was highlighted by clips from past telecasts, a visit by the show's first contestants, and the final mystery guest, who was John Daly himself. Daly had always been the emergency mystery guest in case the scheduled guest was unable to appear on the live broadcast, but this had never occurred. Mark Goodson, Bill Todman and Johnny Olson appeared on-camera as well.[47][48][49]

With the end of the original What's My Line? Goodson-Todman struck a deal with CBS's syndication arm (now Viacom) to syndicate a new weekday videotaped edition. This version became a staple of local stations' afternoon and early evening schedules, especially from the 1971-72 season onward, when the FCC forced networks to cede one half-hour to their affiliates. The Prime Time Access Rule was intended to permit local stations to produce news and public affairs programming, but instead many of them turned to programs like WML, as practically all stations outside the largest markets found it unprofitable to produce their own shows locally. The first three seasons (1968-1971) were taped at the Ed Sullivan Theater, [50] before they eventually moved to the NBC Radio City Studios at 30 Rockefeller Plaza, [51] for the last four seasons (1971-1975).

The revival was considered by producers a merger of What's My Line? and its 1950s spinoff, I've Got a Secret, which resulted in noticeable changes from the original. As with Secret, contestants frequently demonstrated their skill or product after the game. Dollar signs for "no" answers were replaced by sequential numbers. Mystery guest rounds were no longer scored and simply ended with a correct guess or when time ran out. Added was a new game, "Who's Who?", in which four audience members, selected before the show, stood on stage with four occupations indicated on cards and panelists would attempt to place the correct occupations with the contestants.

The set, designed by veteran Goodson-Todman art director Ted Cooper, was predominantly blue and featured walls behind panel and host areas tiled with illustrations representing various occupations. The final 1974–1975 season used a set by Ron Baldwin and was red and yellow with blue walls with scattered question marks. Also, the hosts and panelists discontinued formal dress. However, the color animated intro of the final CBS season was reused for the main title sequence from 1968 to 1974.

A bright, contemporary music package was composed by Charles Fox. According to Fox's book, Killing Me Softly: My Life in Music, Robert Israel of Score Productions paid him a buyout fee of $1,000 for the work. The music was performed and recorded at CTS Studios in Wembley, England, with Fox, Israel and producer Mark Goodson in attendance.[citation needed]

Johnny Olson continued as announcer until 1972, after which a succession of guest announcers were used including Wayne Howell, Dennis Wholey, Bob Williams, Jack Haskell, and Chet Gould,[52] with Gould eventually taking over full-time in early 1973.

In 1971, Bennett Cerf died during the show's run. Stations continued to air shows where he was a panelist resulting in confusion among some fans, who were seeing "new" episodes with Cerf, long after hearing about his death. At the time, syndication involved tape sharing between stations airing series, with some having to air episodes later than others. This prompted producer Gil Fates, who recalled the situation in his book, What's My Line?: TV's Most Famous Panel Show, to send a form letter response to fans who had written complaining about the late Bennett Cerf's failure to disappear, some saying the television stations were using poor taste. Fates explained that Cerf indeed had died, but television was practicing a time-honored tradition of celebrating one's work long after their death. As he wrote in his book, Fates knew, but did not tell viewers, about the production costs that would have gone to waste had his company acceded to the demands, some coming from station managers, to scrap the Cerf tapes.[53]

The syndicated version ran for 1,315 episodes. In the fall of 1975 the final tapings aired in most parts of North America.

Larry Blyden, informed of the program's termination, was offered a job hosting a new Goodson-Todman game show, Show-Offs. He was killed in a car accident in Morocco at the age of 49, a few weeks after taping the pilot.

New versions of WML were planned as early as 1981, and in recent years Harry Anderson was announced as host of a 2000 revival. None of these revivals ever made it to air. In 2014, another pilot for a revival was shot to offer to stations in 2015.

In early 1975, with production of the syndicated version of the series on break, the show's staff went through the annual process of selling the syndication rights to TV stations across North America. That year, there were not enough takers to justify further production.[54] Just days after disbanding their technical crew, Goodson and Todman pitched the idea of a retrospective network special to celebrate the 25th anniversary of the program's CBS debut, called What's My Line at 25. The programming department at CBS turned down the idea[55] but ABC bought it. The special was broadcast by ABC on May 28, 1975, and is currently available for viewing at The Paley Center for Media. It made a return to television as a one-time rerun on Game Show Network on December 25, 2014 at 1:00 A.M. EST.

In producing the special, the only existing records of the original series on kinescope film were removed from storage and brought to a Manhattan editing facility that Goodson-Todman Productions rented. There, company employees Gil Fates, Bob Bach, Pamela Usdan and Bill Egan[55] worked round-the-clock for three days to compile the 90-minute special under deadline pressure from ABC network official Bob Shanks.[56] In the process of viewing and editing the films for the special, they accidentally damaged or destroyed several kinescope films which spanned the entire run of the original series, including a few that did not make the final cut of the retrospective.[25] In addition, some unspooled film remained on the floor after the group's rented time at the facility ran out.[25] An April 1967 episode featuring Candice Bergen as the mystery guest was lost in its entirety, as was a June 1967 episode featuring both Betty Grable and F. Lee Bailey. Other episodes sustained only partial damage, such as a 1965 episode that is mainly damaged during the mystery guest appearance of Marian Anderson.[citation needed]

In 1980, Mark Goodson-Bill Todman Productions, creators of What’s My Line?, produced That's My Line which also highlighted the unusual occupations of ordinary people. However, the show was developed as a reality show and had no panel or game elements. What’s My Line? announcer Johnny Olson was the announcer for the show which ran for two seasons on CBS.

In addition, the show has featured relatives of the original cast: Jill Kollmar (daughter of Dorothy Kilgallen and Richard Kollmar), Nina Daly (daughter of John Charles Daly), and Vinton Cerf (co-inventor of the Internet and distant cousin of Bennett Cerf). It also included a segment in which Vint Cerf's son Bennett (named after the panelist) appeared as a guest.

All original series shows were recorded via kinescope onto film, but networks in the early 1950s sometimes destroyed such recordings to recover the silver content from the film.[58] CBS regularly recycled What's My Line? kinescopes until July 1952, when Mark Goodson and Bill Todman, having realized it was occurring, offered to pay the network for a film of every broadcast.[citation needed] As a result, only about ten episodes exist from the first two years of the series, including the first three broadcasts.

The existing kinescope films (now digitized) have subsequently rerun on television. The series has been seen on GSN[59] at various times.

An Australian version hosted by John Barnes debuted on station TCN-9 in 1956 during the opening week of Australian television and ran until 1958. It was replaced by a long-running version of To Tell the Truth. The archival status of this version is unclear.

The Brazilian version of What's My Line? was called Adivinhe o que ele Faz? ("Guess What He Does?") and was hosted by Heloísa Helena. On December 16, 1956 Helena appeared as a contestant on the American version.[61]

Was bin ich? ("What am I?") ran on ARD (First German Television) from 1955 to 1958 with Robert Lembke (a Bavarian) as host.[65][66] Lembke was head of the news division of the public Bavarian Broadcasting Establishment Bayerischer Rundfunk (BR) at the time and had bought the rights to the series during a visit to the BBC in 1954.

Guests received 5 Deutsche Mark (DM) for each "no" answer and the panel was allowed 10 "no" answers. Prize money was given in a porcelainpiggy bank, and Lembke used to insert a 5 DM coin into the Bank's slot for each "no", producing a loud, characteristic sound. In relation to this, Lembke's most famous line "Welches Schweinderl hättens denn gern?" ("Which piggy would you like to have?", spoken in Lembke's strong Bavarian accent), which referred to differently-colored piggy banks.

Playing rules were almost identical to the original American rules on What's My Line with two notable exceptions:

Before starting into the line of questions, Robert Lembke would ask the regular guests to perform a "typical gesture" that would occur regularly in their line of working, but wasn't recognizable too easily. A hairdresser, for example, would not perform the gesture of combing a customer's hair but of simply lifting a strand of hair before using the comb.

The "celebrity guest of honor" (German equivalent to the "mystery celebrity guest") would receive neither a piggy bank nor money to fill it, but accessories to something he would indulge in privately, ascending in value. So, if a secret guest of honor would (e.g.) be a painter in his private time, he would receive something like a small paint brush on the first "no" up to an easel on the tenth "no". A keen reader would receive up to ten books by his favorite authors, et cetera.

The Indonesian version is called Kuis Siapa Dia ("Who He/She Is"). First premiered on August 3, 1992, it was one of the most successful and legendary quiz show in Indonesia. Created by Ani Sumadi. After 15 years, the show is aired again on Trans 7 TV station starting from 27 Oktober 2014.

The South Korean version began in 1956 by the South Korean government and run as a non-profit organization.[68] On July 28, 1963 a panelist from this version, Miss Keun Oh Kim, appeared as a contestant on the American version.

There was also a radio version for British listeners on Radio Luxembourg. As Andrews and Harding had exclusive contracts with the BBC, their places were taken by Peter Martyn (later Bernard Braden) and Richard Attenborough. Original-series regulars Nixon, Barnett and Kelly also appeared.

The programme aired for a further two series from 1989 to August 28, 1990 with Rippon as host. The Keith and Rippon episodes were taped and screened in ITV's daytime schedule.

The show was revived by HTV West and Meridian from September 20, 1994 to December 17, 1996 hosted by Emma Forbes. A special one-off edition hosted by Hugh Dennis was produced for BBC Four in 2005, as part of a season about British culture in the decade following World War II, along with an episode of the original series, from October 5, 1957.

The Venezuelan version was called Mi Trabajo y Yo (roughly, "My Job and I"). On December 24, 1961 the director and moderator of this version, Jacques Lemoine, appeared as a contestant on the American version.[74]